Progeria kidney has abnormal mesangial collagen distribution

It has been suggested that progeria, a congenital disorder associated with clinical features that resemble premature aging, may be the result of a connective tissue abnormality. Although to date the clinical and pathologic features for 14 autopsied cases of progeria have been reported, details as to the renal changes in progeria are scanty. We investigated the histological features from a male and female with progeria who died aged 11 years and 20 years respectively. In our young male subject there was no glomerulosclerosis, while the kidney from the older subject showed focal renal scarring with focal glomerulosclerosis and associated tubular atrophy. Two small papillary adenomas were present within the renal cortex of the latter subject. In both cases non-sclerotic glomeruli were moderately enlarged with expansion of mesangial matrix. Immunohistochemical detection of collagens showed absence of collagen I and III within the mesangium of non-sclerotic glomeruli, while there was moderate to marked expression of collagen IV, V and VI. Collagen V is thought to be involved in matrix assembly while collagen VI probably has a regulatory role in extracellular matrix development and these are either not seen or are very weakly expressed in normal renal mesangium. The distribution of collagen within the mesangium of progeria kidney is evidence in support of the concept that progeria is a primary connective tissue disorder.